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By F Carrick, W A. Ellis, D R. Mulligan, S I. FitzGibbon

"One of the major environmental impacts of mining is the destruction of habitat. The koala (Phascolarctos cinereus) is an iconic Australian marsupial that has been severely affected by land clearing and its decline is continuing. This has placed pressure upon mining companies and government agencies to ensure koalas are managed throughout the life-of-mines - from land clearing through to rehabilitation of post-mining landscapes. This paper reports on the æKoala VentureÆ research partnership between The University of Queensland and Rio Tinto. As part of the Koala Venture program we examined koala use of two types of restored environments: rehabilitated mined land (20 sites) natural regrowth forests (six sites), at Blair Athol Coal Mine in Central Queensland, Australia. Searches for koala scats revealed evidence of koalas in ten per cent of rehabilitated sites (2/20) and 33 per cent of natural regrowth sites (2/6). Two factors were identified as being of greatest importance in facilitating koala recolonisation of restored habitats. Firstly, all recolonised sites were located close to native forest occupied by koalas (mean 135 m ¦ 52). Proximity to source animals is considered crucial to recolonisation of suitably restored habitats. Secondly, three of the four recolonised sites were dominated by koala food trees, most of which were large enough to be utilised by koalas. Availability of suitably abundant food resources is, therefore, also considered crucial. The requirement for these two factors, in combination, is highlighted by the absence of koalas at several sites that contained abundant food trees, but that were distal to areas with source animals, and vice-versa.Our research demonstrates the enormous potential for restoration of wildlife habitat on post-mining lands, even for species with specific requirements such as the koala. Consideration of the ecological requirements of wildlife during rehabilitation planning is critical to enhancing the likelihood of recolonisation.CITATION:FitzGibbon, S I, Ellis, W A, Mulligan, D R and Carrick, F, 2012. Rehabilitating post-mining landscapes for wildlife - A case study from the Koala Venture research program in Central Queensland, in Proceedings Life-of-Mine 2012, pp 319-324 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By A G. Tomkins

"Approximately 32 per cent of the worldÆs total gold production has come from greenstone belts (Frimmel, 2008). In these regions numerous small to large, quartz vein-associated gold deposits are hosted in metamorphic rocks ranging from lower greenschist to granulite facies. Historical exploration has focused its efforts on rocks of greenschist to lower amphibolite facies because these seem to contain the most deposits. Consequently, these regions are now reaching mature brownfield status, particularly in developed nations, and finding new deposits is becoming progressively more difficult. In comparison, regions of similar tectonic setting, but instead containing high-grade metamorphic rocks of mid-amphibolite to granulite facies, have received little attention because the first explorers found fewer deposits there.However, these regions certainly do contain some very significant gold deposits such as Hemlo in Canada (~684 t Au), Renco in Zimbabwe (~31 t Au mined since 1980), the very profitable Challenger deposit in South Australia (~36 t Au; recovered + reserve + resource), and the most recently discovered Tropicana deposit in Western Australia (~182 t Au; reserve + resource). High-grade metamorphic terrains therefore offer explorationists an excellent opportunity to move onto relatively green fields within developed nations, which carry less risk associated with development. However, explorationists have comparatively little knowledge of the geological controls on gold distribution in high-grade terranes because: industry experience lies in traditional lode-style gold deposits these gold deposits are geologically more complex there has simply been minimal research conducted on these deposits as a holistic group.Furthermore, research conducted in the last five years has shown us that the previous widely accepted model for gold genesis in these terranes, the crustal continuum model, is incorrect. Here, I discuss features from several gold deposits hosted in high-grade metamorphic rocks and use these to define two categories for explorationists to consider: deposits that formed prior to peak metamorphism (metamorphosed gold deposits) deposits that formed well after peak metamorphism (post-metamorphic gold deposits). There are none that have been convincingly shown to have formed during peak metamorphism.CITATION:Tomkins, A G, 2013. Gold deposits in highly metamorphosed terranes, in Proceedings World Gold 2013, pp 23-26 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

In the geologically prospective nations which rim the Pacific Ocean, mineral deposits offer great potential to create wealth for social and economic development. The paper first examines the geological and economic attributes of potential mineral wealth based on current outlook assessment of all significant base metal deposits discovered to 1988 in two Pacific Rim nations - Australia and Canada. The variability of mineral wealth among the economic deposits evaluated and the major contribution of the few world-class discoveries to total mineral wealth are highlighted. Then, the essential but too often neglected linkage between the makeup of potential wealth and its actual realization is analyzed. The impact of taxation and the role of exploration are crucial in this regard. Finally, the ingredients of exploration success, prerequisites for realizing the mineral wealth of nations, are examined.

Jan 1, 1995

By Langberg D, Gray N. B

The flocculation of hydrophobic magnetite with gold was examined as a possible means of recovering fine (95 per cent were possible for 1.5 - 3.0 ¦m and 5.5 - 7.5 pm gold sizes. The effect of process variables on the flocculation process was explained by variations in the adhesive force between the gold and magnetite.

Jan 1, 1991

Tomago sandbeds is an unconfined coastal aquifer located 20km. north of Newcastle in New South Wales, Australia. These sandbeds extend over an area of about 130km. The average aquifer depth is about 20m. with a mean transmissivity of about 400sq.m/day and a specific yield of about 0.2. The city of Newcastle and surrounding areas derive water from Tomago for potable purposes. The average extraction being about 50 ML/day. The iron value of the ground water varies between 5 and 15mg/1. This iron is removed by a conventional water treatment plant using Alum. The aquifer whilst principally quartzose also contains deposits of heavy minerals like rutile, zircon, ilmenite, etc., The mineral sand mining has been in progress at Tomago since 1972. Mining is carried out in a con- structed pond with a water depth of about 5m. on which is floated a suction cutter dredge that moves across the front of the pond using a water jet to entrain the soil from the ground surface to the bottom of the mineralised zone. Effect of mineral sand mining on ground water quality, particularly iron, was the subject of intensive investigations undertaken at Tomago since 1970. The effect on water quality was studied by collecting and analysing water samples from network of observation wells established during the period of mining. Water samples were collected about 4-5 years prior to mining and analysed for iron, sulphate, chloride, pH, etc., After mining the observation wells were re-established at the same locations and water samples were collected and analysed for at least 5 years after mining. Water samples collected from majority of the observation wells indicate an increase in iron levels. The level of increase is very site specific. The increase in iron is also

Jan 1, 1987

By Mimura K

The carbon reduction of tantalum pentoxide was investigated in a plasma-arc furnace. The sample was a mixture of tantalum pentoxide and graphite, vacuum pressed into a briquette and was reduced at about 3100¦C. Argon was used as the are gas. The optimum mixing ratio of carbon and tantalum pentoxide, C/Ta205 is 5.10--5.15. The sample, weighing 7 g is fused within 60^ 70 seconds by plasma-arc heating and the reduction of molten tantalum oxide with solid carbon pro- ceeds rapidly to approximately 99.5 % Ta during this period. The reduction that follows in the molten state is slow. Within about 10 minutes, the maximum tantalum content of the massive metal product reaches 99.9 % and the oxygen and carbon remaining in the product are 50 ppm and 400. 500 ppm respectively.

Jan 1, 1980

By Dif A. E N, Abdalla MH

The effect of multiple tunnels /cavities on the stress and deformation field of the soil media was investigated by using a two dimen- sional plane strain boundary element model. The soil was considered as an elastic, isot- ropic and homogenous media. The interaction of two circular and parallel tunnels/cavities was investigated. Depth of burial, tunnel spacing and surface load width were the system variables considered. The results of this study indicated that the vertical displacements of the soil media increases by decreasing the distance between the adjacent openings, the interaction between the two tunnels/cavities can be neglected for K/D > 5, while the load width has a minor effect except in the dis- tance of D from the center line of the load and for a depth of 2D.

Jan 1, 1987

By Theophili CN, Kapenis AP

Seismic tomographic imaging has been applied to determine the blast induced damage zones in bauxite pillars in underground mining. At the retreating stage, when pillar dimensions are reduced from 8 x 8 m to approximately 5 x 5 m, the' seismic tomographies reveal, through measurements of the P-wave velocities which is a measure of the degree of fracturation of the pillar rock mass, the presence of three zones within each pillar. In the external zone, where velocities recorded are below 750 m/s. extensive pillar damage occurs which is attributed to both the growth and coalescence of pre-existing cracks and even the creation of new cracks in the rock mass. This effect is in agreement with literature, when considering the peak particle velocity as a criterion for rock failure in tunnels. In the intermediate zone, where velocities range between 7S0-1000 m/s, damage to a much lesser extent occurs which is due mostly to growth of pre-existing cracks and widening of their apertures. The inner zone, where velocities exceed 1000 m/s, is considered to be unaffected by blasting. Simple remedial measures of low cost, which are based on blasting mechanics are proposed to minimise the blast induced damage zone and consequently the transition zone.

Jan 1, 1995

Tourmaline-bearing rocks are a rare rock type of Suites 3, 4 and 5 at Broken Hill. Minor laminated plagioclase-quartz-tourmaline rocks occur in association with the quartz- magnetite rocks of Suite 3 with the greatest abundance of tourmaline-bearing rocks present in Suite 4 intimately associated with lode horizon, scheelite mineralisation and zinc mineralistion - all approximate strike equivalents of the Broken Hill Pb-Zn-Ag deposit. Bedded quartz-tourmaline rocks, tourmalinites, tourmaline-rich pelite and tourmaline-bearing lode horizon have been recorded from suite 4. The bedded tourmaline rocks rarely display cross bedding, graded bedding, slump structures and small scale intraformational breccias. Minor tourmaline-gahnite-bearing pelites are present in Suite 5. The sedimentary structures, metamorphic textures, the stratigraphic position of the tourmaline-rocks and the presence of quartz-tourmaline-gahnite-spessartine (-fluorapatite) lode rocks indicates that the mineralisation at Broken Hill and the tourmaline-rich rocks are all products of submarine exhalative hot spring systems which were most active during deposition of Suite 4 rocks. Tourmaline is chemically different from that associated with granitic activity and from other submarine exhalative tourmaline-rich rocks because the premetamorphic alteration at Broken Hill involved addition of Fe, Ti and F and subtraction of Mg - a feature reflected in the chemistry of tourmaline from Broken Hill.

Jan 1, 1983

In 1985 BMR assessed Australia's economic demonstrated resources of mineral sands as follows: rutile 8.0 Mt, ilmenite 41.4 Mt, zircon 11.5 Mt, and monazite 229 000 tonnes. These resources are located along the east coast of Australia, in the southwest corner of Western Australia, and in the Eneabba region, north of Perth, WA. However, over 40% of Australia's rutile and zircon resources, particularly those on the east coast, are presently not available for mining because of environmental considerations. As well, east coast ilmenite has been considered unsuitable for use by sulphate route pigment producers because of its relatively high chrome content. World demonstrated resources of rutile and zircon are estimated by BMR as 29 Mt and 38 Mt respectively. Demonstrated resources of ilmenite amount to about 1 billion tonnes. These occur predominantly in hard rock deposits in Norway, Canada, USSR and China, as well as alluvial deposits in Australia, South Africa and India. Quantitative data for world monazite resources is sparse. However, world production of rare earth oxides is now mainly from bastnaesite, a hard rock resource. Australia is presently the world's principal producer of rutile and zircon, and also provides a major share of the world's ilmenite. With the expected increase in Australia's rate of output of these commodities, combined with restrictions on mining along parts of the east coast, its position could diminish substantially over the next 25 years.

Jan 1, 1986

By G M. Taylor

The application of high technology to monitor and control fire life safety, critical functionality in tunnels and underground spaces generally has progressed at an ever accelerating rate over the past decade. Today these systems comprise some of the most complex and little understood aspects of the tunnel/underground facility construction industry, with this area being perceived as high risk comprising impenetrably complex ‘black box’ technology covered in blinking LEDs. This paper will seek to explode some urban myths and common misconceptions associated with such systems, providing its intended audience with a review of what all this technology comprises and where the real risks lie in its delivery lie.The author contends (and looks to support such contention via this paper) that by applying baseline project and risk management processes to the procurement of this widely misunderstood black box technology, the quality of the final outcome can be much improved, driving innovation, reducing both cost and significantly mitigating delivery risk.CITATION:Taylor, G M, 2014. Procuring control and intelligent traffic systems for major new build projects – avoiding pitfalls and maximising value, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 113–120 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Abbott T. M

Alcoa of Australia operates three Alumina refineries in the South West of Western Australia at Kwinana adjacent to the South suburbs of Perth and at Pinjarra and Wagerup in rural settings 100 and 150 kilometres south of Perth respectively (see Figure 1). Alcoa's total alumina production is currently around five million tonnes per annum and this will increase to 5.5 million tonnes by early 1990. Further expansion of production is likely if current world aluminium demand trends continue. Alcoa's refineries utilise bauxite mined in the nearby Darling Range which is low grade by world standards having around 32 % by weight extractable alumina (by comparison Weipa bauxite yields around 55% alumina). This means that for every tonne of alumina produced two tonnes of solid wastes remain and therefore while we in Western Australia can boast of hosting the largest alumina industry in the world with around 18% of total world production we suffer from having the lion's share or 40% of the world's bauxite residues to dispose of. In its Western Australian setting the management of these residues in a manner which is acceptable to the community creates many challenges. These are primarily due to the mass and volume of waste produced, its chemical and physical characteristics and the environmental features of the local area including close proximity of neighbours, competing land uses and the presence of natural resources such as surface water and groundwater. In addition the trend towards more stringent statutory environmental controls and greater political and community awareness of environmental issues means that we must be able to demonstrate improvements that will reduce the considerable adverse impacts of past practices. Of course we must also try to keep the overall cost of residue disposal as low as possible to maintain our competitiveness with refineries which may have much smaller volumes of waste to dispose of and less environmental constraints.

Jan 1, 1989

By J L. Mauk

The Favona adularia-sericite epithermal Au-Ag deposit is located at the southern end of the Hauraki Goldfield, about one kilometre southeast of the world-class Martha deposit. The deposit occurs in Late Miocene andesitic lava flows and local dacitic tuffs of the Waipupu Formation. In some places, post-mineralisation ash fall and ignimbrite, up to 50 m thick, cover mineralised rocks and andesite. We collected soils samples from 110 sites along eight traverses over Favona, and from three regional lines: two south of Favona, and one north of Favona.   Analyses of soils identify prominent enhanced concentrations of Au, Ag, and Hg, and lower enrichments of Sb and As. At Favona, Au and Ag appear to be highly anomalous in areas over mineralisation with Au concentrations greater than 100 ppb and Ag concentrations greater than 1000 ppb, whereas background concentrations are approximately 5 ppb and 50 ppb respectively. The background concentrations of Hg in soils are approximately 100 - 200 ppb, but in mineralised areas, Hg generally exceeds 200 ppb, and some soils contain greater than 600 ppb. Antimony shows enrichments, although weak, above known veins and As locally shows some enrichment above areas of known mineralisation. Therefore, soil sampling at Favona defines geochemical anomalies that correlate with the position of known mineralisation at depth. Thus, there is strong empirical support for the use of Au, Ag and Hg, and possibly Sb and As geochemistry to identify mineralised trends associated with buried deposits at other epithermal prospects.

Jan 1, 2007

An empirical method of estimating dense rock (D.R.E.) equivalent volumes erupted as airfall tephra, described in a companion paper in this volume, is elaborated, and its accuracy discussed. Estimates obtained from a single eruption can be classified as to whether they show positive, negative, or constant relative dispersion. For positively dispersed tephras (estimated volumes increasing with distance), this procedure improves the accuracy of the method. The technique is applied to selected andesitic tephras erupted from Egmont Volcano, New Zealand, during the last 28 000 years, which are found to range in volume from about 1.5 x 107 m3 up to about 2.4 x 108 m3 D.R.E. With a factor of about 16 between the smallest and largest volumes, this contrasts sharply with the rhyolite volcanoes in New Zealand, where the difference factor is usually of the order of 100. The largest tephra eruptions at Egmont are small compared to the largest debris avalanches, which have exceeded 1010 m3 (10 km3) in volume.The magnitude versus frequency relationship, calculated using a maximum likelihood method, establishes the limits of eruption magnitude at Mt Egmont as 107 to 109 m3 D.R.E. For some volcanoes, the magnitude-frequency relationship changes with time, owing to clustering of eruptions, separated by long dormant intervals. Ngauruhoe Volcano, New Zealand, is an example. Within eruptive episodes, the mean interval between eruptions of >_ 105 m3 is about 0.9 ¦ 0.65 years. The mean interval between eruptive episodes in which >_ 106 m3 is erupted, including episodes in which this volume is erupted gradually, is about 25.8 ¦ 6.6 years, and the mean dormant interval between all episodes is about 5.2 ¦ 3.0 years. At present Ngauruhoe is in an unusually prolonged dormant period, 50% longer than any in the historical record, since 1839.

Jan 1, 1990

Blast Engineers frequently use the terminology "the blast showed good heave", or even "the heave was better this time". It is reasonably obvious that "good" and "better" are not the best terms to use. It is also noted that any variation in the data can be misleading. The author proposes a more precisely defined and objective set of measures as tried and tested in a project in 1988. Simple objective measurements of a muck pile profile can measure 1. distance thrown 2. spread of material 3. heaping of material 4. skewness, or bias in the heaping 5. rotation of the mass This technique enables one to compare the profiles from different blasts without relying on subjective experience or judgement. Simple, artificial profiles will be presented to illustrate the problems of description; and then application of the measurement techniques to these profies will be discussed with physical interpretations. The mathematical techniques will be presented, and results of the application of the techniques to real data collected during research carried out at Baimsdale in Victoria, will be presented as illustration. The use of these techniques in mathematical modelling will be discussed.

Jan 1, 1990

By Pinter R

Several major routes connecting Northern and Southern Europe or Asia run through Austria. These highways have to surmount the alpine range which traverses Austria from west to east. In order to ensure safe driving conditions even in winter, tunnels, at times quite long ones, are necessary. Austria now has tunnels totalling 160 km in length. These tunnels are either already in use or just about completed. The Plabutsch tunnel near Graz will be one of the longest tunnels in the world: approximately 10 kilometers in length. It will be put into operation in the summer of 1987. Before construction could begin, soil and rock conditions had to be investigated by means of a test tunnel. Afterwards, excavation was begun to the full 100 m' cross section. The new Austrian tunnelling method with conventional blasting was used for the major part of the tunnel. It was necessary to have such a large tunnel cross section because a fully transverse ventilation system is installed for environmental reasons. In order to avoid air pollution from the tunnel, exhaust fumes are not allowed to escape from the tunnel portals but from two shafts, each with a diameter of 8.5 m. In this way, exhaust fumes must rise 90 meters or 240 meters before they reach the open air and will thus not affect the city. The ventilation system influences the size of the excavation, and especially the size of the ventilation caverns and the air shafts. All these factors directly influence construction and maintenance costs, and an economical optimisation leads to the appropriate dimensions for the excavation.

Jan 1, 1987

By Palmer C. G, Rowe P. G

Ore handling improvements at Mount Isa Mines Limited were necessary to keep abreast of technological advances in all phases of sublevel stoping practice.In the early 1930s an efficient ore handling system was in operation.However in 1936 excessive water encountered in deepening the hoisting shaft necessitated the sinking of a second hoisting shaft. Financial difficulties prevented abandoning the original shaft and surface ore handling and crushing facilities, so ore was transferred underground and underground crushing deferred. It was not until 1951 Jhat multilevel crushing permitted increased efficiency in the handling of ore from stopes. Ore was then hoisted in one shaft and transferred on the surface by conveyor belt to a new crushing plant.In 1956 a planned production increase from 5,000 to 11,000 tons per mining day made possible further improvements in ore handling. Larger equipment was installed and existing equipment modified to capacitate the handling of larger sized ore at increased daily tonnages.INTRODUCTIONThe intensive exploratory programme commenced in 1954 disclosed large reserves of both lead and copper ores and in 1956 an expansion programme was initiated to increase production from 5,000 to 11,000 tons per mining day. The increased tonnage would result in decreased costs per ton and further cost reductions would result from increased mechanisation underground. The combined effect would permit larger tonnages of lower grade ores to be included in ore reserves. To achieve both cost reduction and the scheduled production increase, improvement in ore handling was of vital importance.For efficient and low cost sublevel stoping it is necessary to maintain an economic balance between...

Jan 1, 1961

THE area of the State of New South Wales is not great, nevertheless it has very large and important Mineral Resources. This is the more noticeable when the values of the annual mineral production from the individual States of the Commonwealth arecompared with the value of the New South Wales production. The principal minerals mined now are not gold, copper, and tin, as they were in the early years following the gold rush of 1851, the centre of gravity of commercial mineral activity having moved to coal and "oil-shale," water, limestone (with cement), silver-lead-zinc cadmium, sulphur, slate and other building and ornamental stone, road materials, and clays.From small areas totalling only 650 sq. miles, coal to the extent of 311,000,000 tons, valued at £151,000,000, has been won.The estimate of actual and probable reserves by the Mines Department within an area of less than 1000 sq. miles is about 14,000,000,000 tons, while the potential reserves within the remaining 15,500 sq. miles of concealed coal fields must be enormous. Even taking into account only the actual and pI:obable reserves in the 1000 sq. miles known, and assuming a depletion at the rate of 350,000,000 tons a year, or somewhat greater than that of the British Isles at present, and assuming an average value of £1 a ton, with money at 5% compound interest, then the present value of this coal (40 years of depletion) would be £5,575,000,000 approximately: truly an enormous present value for a business of 40 years, dealing only with 1000 sq. miles of country. The location of the main coal basin in New South Wales is one of great strategic importance. It lies almig and near a seaboard, with excellent facilities for anchorage; the coal is of very high quality, and is readily accessible; the climate is admirable. Were this same coal at Port Darwin, its commercial importance would not be be pronounced.

Jan 1, 1926

The Boddington Gold Mine orebody is a large tonnage, low grade gold deposit located within the Archaean Saddleback greenstone belt within the south-western region of Western Australia. The orebody consists of laterite caprock (30 per cent) and clays (70 per cent) produced by lateritisation of felsic volcanics and intrusives. The caprock comprises gravel, hardcap and B-zone which have a specific gravity of 1.8, 2.4 and 1.8 respectively. The clay has a specific gravity of 1.5.

Jan 1, 1993

The Escondida Porphyry Copper Deposit, located in Chile's II Region 160 Km to the southeast of the city of Antofagasta, is currently owned by Minera Escondida Limitada, a company comprising The Broken Hill Proprietary (57.5%), Rio Tinto Zinc (30%) a group of Japanese companies represented by Mitsubishi Corporation (10%), and the International Financing Corporation of the World Bank (2.5%) (Fig.l)By 1983, most of the reconnaissance drilling was completed and prefeasibility studies were regularly updated as new drilling results were reported and project concepts re-evaluated (Fig.2). In October 1982 the project was transferred from Exploration Management to Operations. By the end of 1984 project pre-development activities, including inpit development drilling, geological exploration, water resource definition, an underground bulk sampling program and the initial project feasibility report, were completed.

Jan 1, 1990